Sharpener for lawn-mowers.



J. ONSEL.

SHARPBNER FOR LAWN MOWBRS.

APPLICATION FILED AUG. 5, 1914.

1,130,624. Patented Mar. 2, 1915.

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NORRIS PETERS CO, PHOTO LITHDQ WASHINGTON. D. C.

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enn oirsnn, on Basins-sun, OHIO.

To all whom it may concern:

Be it known that I, JOHN Onset, a citizen of the United States, and aresident of Iliisingsun, in the county of Wood and State of Ohio, haveinvented a certain new and useful Sharpener for Lawndviowers; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such aswill enable others skilled in the art to whichit appertains to make and use the same, reference being had to theaccompanying drawings, and to the characters of reference markedthereon, which forma part of this specification.

Myinvention relates to automatic sharp modified form thereof areillustrated in theaccompanying drawings, in which,

Figures 1 and 2 are front and cross-sectional views respectively of alawn mower equipped with my invention, Fig. 3 is an enlarged outer enddetail of the invention, Fig. l is an end view of a sharpening stone andits holder, Fig. 5 is an outer end view similar to Fig.3 with thebinding nuts re moved from the stone holding parts, Fig. 6 is anenlarged rear elevation of a grinding stone, its holder and carryingarms, with parts in section and broken away, and Figs. 7 and 8 are endand side details, with the latter partly in section, of a modified formof the invention. a

Referring to the drawings, 1 designates thecutter wheel of a lawn mower,which wheel is provided with a plurality of knives 2. i

3 design ates the customary cross or guardbar of a mower such bar beingcommon to most makes of lawn mowers. Removably carried by and projectingupward and rearward from the guard-bar 3 for revoluble adjustmenttherearound are a pair of arms 4, one being located adjacent to each endof I Specification of Letters Patent. Patented ltfEay, 2 1915Application filed August 5, 1914. Serial N 0. 855,143. r i

of such free end portion in vertical planes,

as shown. The vertically flattened portion, of each. arm preferablyextends upward. rearward and downward on a curve from the U-shapeporticn5 thereof, with the free end thereofterminating in substantially verti-.CEtl-DOSIUOH and provided with a slot? which, in the present instance,is of inverted T form.

The grinding medium comprises a stone l ke bar 80f any suitable grindingcompositionor 1t mav comprise a natural grinding stone. as desired, suchbar being of a length substantially equal to the length of the knives 2of the mower. The sharpening bar 8 is carried by and has its upper edgeportionproiected into the bottom channel of a holder-bzirbr member 9being secured therein by a plurality of set-screws 10, which threadthrough one wall of the channel portion of the member and preferablyhave their inner ends thrust directly againsta metal plate 11, which inturn has its thrust against the sharpening bar 8. It is found inpracticethat the iar of the lawn mower, when being operated, will loosenthe engagement of setscrews with the grinding stone and that theinsertion of a thin plate 1 between the set-screws and the stone willprovide a more eiiicient and lasting gripping means than if theset-screws have direct contact with the stone. The ends of theholder-bar channel are open so as to completelv'expose the ends of thestone.

Promoting from each end of the holder bar Oabove its channel andlengthwise therei of is a threaded. stud 12. which is intended toproiect through the slot 7 of the respec tive arm 4 and to receive a nut1 at its uter end "for effecting a firm clamping of the arm 4 inproperly adjusted position to the end of thesholder.

. It is preferable when making the stone 8 to provide the samelengthwise thereof with an internal reinforcing bar 14 the ends of endsof the stone.

which are projected beyond the ends of the stone and threaded, as at 15,to extend through the lower transversely broadened portion of the armslot 7 to receive a binding nut 16, whereby the ends of the arms 4 havea firm clamping action against the respective As the clamping of themetal arms4 directly to the material forming the stone 8 would not be ofa very lasting or permanent nature due to the crumbar 14 performs a dualfunction namely of reinforcing the stone and of assisting in firmlysecuring the arms to the stone, which securing means augments theclamping action of the set-screws 10, which "alone are customarily usedin sharpeningdevices of this nature. The broadening of the lower portionof the slot 7 of each arm enables the holder 9 and its stone to have, aswinging action relative to the arms 4, with the studs 10 as theswinging axis whereby to facilitate an adjusting of the stone to suitthe knives.

In the modified form shown in Figs. 7 and 8, the stone reinforcing bar,which is designated 14 therein, terminates substantially flush with theendsof the stone, and. the free end portions of the holder carryingarms,

and arms.

'it to suitthe knives.

which are designated 4,are intended to have binding contact with therespective ends of the bars, the tightening ofthe-arms against the barsalone being effected by the nuts 13 of the holder studs 12. The slots 7'of the arms through which the studs 12 project are vertically elongatedto facilitate a relative adjustment of the stone holder It is evidentthat I have provided a simple and eflicient sharpening device, the stoneholding member of which is carried at each end thereof by asingle-piecearm, which is clamped for revoluble adjustment to the guardbar 3 of the lawn mower, and that the stone holding member is carried bysaid arms for adjustment in a simple and efficient manner, thus makingit easy to apply the device to alawn mower and to adjust It is alsoevident that the clamping of the arms againstthe ends of the stone oragainst metal parts carried by the stoneprovides an efficient and secureclamping means for the stone thereby enhancing the practicabilityandficommercial I value of apparatus of this character.

Having thus described my invention, What Copies of this patent may beobtained for I claim as new, and desire to secure by Letters Patent, is,o

1. In combination, a grinding stone of bar-like form, a holder memberfor said stone having studs projecting from its ends,

ing said studs, and means cooperating with said studs to secure the armsto said holder member and to cause the arms to have a 7 arms adjustablysecured to the ends of said bar and having clamping action against theends of the stone.

3. A. sharpening device of the character 1 carrying arms havingapertures for receivdescribed having a sharpening stone provided withmetallic end portions, carrying arms for said stone and means forcausingsaid arms to have frictionalbinding contact with the metallic endportions of the stone.

4. In a device of the character described, a bar-like grinding stone, areinforcing member embedded in said stoneand exposed at the endsthereof, carrying arms for said stone, and means for frictionallyclamping the arms in adjusted relation to the exposed end portion ofsaid reinforcing member.

5. In combination, a bar-like grindlng stone, reinforcing means embeddedin the stone and having parts projecting from the ends thereof, carryingarms having apertures for receiving said parts, and means for co-actingwith said parts to frictionally clamp the arms to the stone.

6. In'combination, a holder member having a channel with its endsopen, agrinding stone mounted in and projecting transversely from said channel,means for securing the stone in said channel, studsprojecting from theends of each said holder member and stone, carrying arms slotted toreceive said studs,'a-nd means cooperating with said studs to adjustably clamp the arms tosaid member and stone. Y Y

7. In combination, a channeled stone holding member, a pair of membercarrying arms, a grinding stone carried by said member, and means foradjustably clamping the free ends of the arms to said member and holdingthe stone in predetermined adjustment.

In testimony whereof, I have hereunto signed my name to thisspecificationfin the Jresence of two subscribin witnesses.

five cents each, by addressing the Commissioner of Patents,

Washington, 13.0. p

